Inflammatory Phenomena and Fibrosis in Androgenetic Alopecia

Abstract

In androgenetic alopecia the genetically predisposed hair follicles are susceptible to androgen-stimulated hair follicle miniaturization, leading to replacement of large and pigmented hairs by barely visible depigmented hairs. The result is a progressive decline in visible scalp hair density that follows a defined, age- and sex-dependent pattern. Major advances have been achieved in understanding peculiarities of the androgen metabolism involved. Nevertheless, clinical practice has shown that simply blocking androgens has only limited success. On histologic examination, the miniaturization of terminal hairs is frequently associated with perifollicular inflammatory phenomena, and eventually fibrosis. Therefore, sustained microscopic follicular inflammation with connective tissue remodeling, eventually resulting in permanent hair loss, is considered a possible cofactor in the complex etiology of androgenetic alopecia.